Novel modifications of elemental nitrogen and their molecular structures – a quantumchemical calculation

Using the quantum-chemical calculation methods QCISD and G3, the possibility of the existence of nitrogen molecules with the composition N4, N6, N8 and N10 has been discussed. On the basis of the data obtained, the conclusion about possibility of existence of three novel polymorphic modifications of elemental nitrogen with an even number of atoms in molecules, namely N4 with rectangular and regular tetrahedron shapes, and N6 in a form remotely resembling an "open book", has been made. The values of bond lengths, valence and torsion angles, and oscillations frequencies in each of the above-mentioned forms of elemental nitrogen have been presented.